Scaffolding systems can be generally divided into three major types of systems, namely tube and clamp systems, frame and cross-brace systems, and modular systems. The tube and clamp systems are extensively used in the industrial sector and are easily adapted to cope with confined spaces where there are many obstructions such as pipes, stairways, structural steel frameworks, etc. These systems require considerable expertise to erect correctly, and are almost always erected by experienced professional scaffold erectors. With the more recent adoption of modular systems, the tube and clamp systems are now primarily used only for infill areas that cannot be effectively serviced by the modular systems.
Frame and cross-brace systems are very common and these systems are typically used by painters, bricklayers, masons and many other trades to provide effective elevated work platforms. These systems may be used in industrial applications for low rise applications or for other specific uses where guardrails and tie-off rules are less stringent. The frame and cross-brace systems are less rigid as there is some pivotal movement of the frames due to tolerances with respect to the cross-braces. In many jurisdictions, the safety authorities reject the use of cross-braces as effective guardrails and often tubular or wooden guardrails are required in addition to the cross-braces. In order to restrict the weight of the frames, which are typically five feet wide and six feet in height, the tubes used in the frames have an outer diameter of approximately 1.69 inches. In contrast, the support posts of the tube and clamp systems are typically of a diameter of approximately 1.90 inches and of a higher load carrying capacity.
Modular systems have also been used for high load applications. These systems are made of pre-engineered components of specific lengths. The components have integral connection devices that allow connection between the different components of the system, and the system is easily erected in different configurations. These types of systems are commonly used in industrial applications such as refineries and power stations. In North America, the support posts of these systems are typically 1.90 inches in diameter. Frames are typically not used in this type of modular system in that frames made of 1.90 inch diameter tube and of a typical width of approximately 5 feet, are too heavy to be easily carried by a worker. As previously, indicated, frame-type systems are typically of smaller diameter tube to keep the weight as low as possible. Typically, the above-described systems are not inter-compatible.
As labour costs continue to rise, there is a preference for scaffolding systems that are easy to erect. In this way the contractors, that are operating on small margins, are able to erect the system quickly and at reduced cost. The frame and cross-brace type systems are fast to erect and easy to use, and do not require the expertise necessary for tube and clamp and modular systems. The use of frame-type systems can result in a labour saving in the order of 35%.
The present invention utilizes a modular scaffold system that advantageously provides inter-compatibility between a support post-type system and a frame-type modular scaffolding system. This inter-compatibility allows for effective use and labour saving where frames can be suitably used while also providing the higher load capabilities of a support post-type modular system where required. The inter-compatibility of the systems allows the various connecting components such as ledgers and cross-braces to be of the same length while maintaining modularity of the system.
It is also desirable to provide a higher capacity vertical member compatible with many existing modular scaffold systems. Preferably this high capacity vertical member includes a simplified securement.